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Cambridge General Certificate of Education Ordinary Level
5070 Chemistry June 2013
Principal Examiner Report for Teachers

CHEMISTRY
Paper 5070/11
Multiple Choice

Question
Number

Key

Question
Number

Key

1
2
3
4
5

A
D
A
A
B

21
22
23
24
25

D
B
B
C
B

6
7
8
9
10

C
D
C
A
B

26
27
28
29
30

B
D
D
D
B

11
12
13
14
15

C
B
C
D
C

31
32
33
34
35

B
A
B
D
C

16
17
18
19
20

D
B
C
C
A

36
37
38
39
40

A
A
A
B
B

General Comments
Candidates found questions 1 and 39 the most straightforward and the remainder of the paper was a good
test of the candidates’ knowledge and ability.
Comments on Specific Questions
Question 8
Magnesium oxide and aluminium oxide are both ionic compounds and therefore conduct electricity when
molten. The temperature range over which both compounds are molten is 2852 to 2880ºC.
Question 15
Zinc is above copper in the reactivity series and therefore zinc is the metal which ionises in the cell shown in
the question.

1

© 2013

Cambridge General Certificate of Education Ordinary Level
5070 Chemistry June 2013
Principal Examiner Report for Teachers
Question 18
In the reaction between iron(II) sulfate and sodium hydroxide, none of the elements gained or lost electrons.
In all the other reactions elements gained or lost electrons.
Question 23
Calcium proved a strong distractor in this question. The metals calcium and strontium are both in Group II of
the Periodic Table and have similar reactions and in their reactions they lose their two outer electrons.
However, strontium ions and calcium atoms do not have the same electronic configuration.
Question 28
Candidates choosing alternative B concentrated their attention solely on the equations showing the
discharge of ions during the electrolysis of aluminium oxide. However one other reaction, namely the
formation of carbon dioxide, takes place at the positive electrode.
Question 34
Only sulfur dioxide in the list of gases was an acidic gas and able to react with limestone.
Question 38
The only structure without a CH3 group in it was more popular with the candidates than the correct answer A.

2

© 2013

Cambridge General Certificate of Education Ordinary Level
5070 Chemistry June 2013
Principal Examiner Report for Teachers

CHEMISTRY
Paper 5070/12
Multiple Choice

Question
Number

Key

Question
Number

Key

1
2
3
4
5

B
B
C
B
A

21
22
23
24
25

C
C
B
A
D

6
7
8
9
10

C
C
C
B
D

26
27
28
29
30

B
B
A
C
B

11
12
13
14
15

B
D
D
A
C

31
32
33
34
35

D
B
B
B
A

16
17
18
19
20

C
D
B
A
B

36
37
38
39
40

D
C
A
B
A

General Comments
Five questions namely 2, 7, 8, 37 and 39 had very high success rates. Conversely, questions 19 and 35
proved difficult and candidates were split between the four alternatives. Over all the paper distinguished well
between the candidates and proved to be a good test of their chemical knowledge.

Comments on Specific Questions
Question 12
Answers to this question were split between alternatives C and D. The key to obtaining the correct answer
(D) was the realisation that chlorine exists as molecules in the gaseous state.

3

© 2013

Cambridge General Certificate of Education Ordinary Level
5070 Chemistry June 2013
Principal Examiner Report for Teachers
Question 19
Sodium hydroxide is an alkali and reacts with the acidic oxide, carbon dioxide, a fact well known by the
majority of the candidates. Many did not realise that the amphoteric oxide, aluminium oxide, also reacts with
sodium hydroxide.
Question 27
Iron and calcium silicate both settle at the bottom of the Blast Furnace in the liquid state due to the high
temperature of the furnace. The iron is not in the solid state as suggested in distractor D.
Question 28
Nitrogen is almost inert and does not react with copper(II) oxide or sodium hydroxide. The only gas passing
unchanged through the apparatus had to be nitrogen. Thus Z was nitrogen and A was the only alternative
with Z identified as nitrogen.
Question 31
Candidates choosing alternative B concentrated their attention solely on the equations showing the
discharge of ions during the electrolysis of aluminium oxide. However one other reaction, namely the
formation of carbon dioxide, takes place at the positive electrode.
Question 34
The most popular distractor was C, filtration. Filtration is a process used to separate insoluble solids from a
liquid. Thus filtration would not remove salt, a soluble compound, from sea water.
Question 35
Alternatives C was almost as popular as the key, A. Candidates opting for C did not take into account that
A, CH3OH, contained oxygen already and C, C3H8, did not.

4

© 2013



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